Mary Owns Two All-Terrain Vehicles (ATVs), Worth $1,000 and $500

Mary owns two all-terrain vehicles (ATVs) , worth $1,000 and $500, respectively. Neil enters into a contract to buy "Mary's ATV" for $750. Mary believes, in good faith, that she is selling the $500 ATV. Neil believes, in good faith, that he is buying the $1,000 ATV. In this situation

A) Mary is entitled to $750 for the $500 ATV.
B) Neil is entitled to the $1,000 ATV for $750.
C) Neil must buy both ATVs for $1,500.
D) the contract is not enforceable.